Journal of the
Korean Mathematical Society JKMS

We give a quotient of the ring $\mathbb Q[A^{\pm 1},t^{\pm 1}]$ so that the Miya\-zawa polynomial is a non-trivial invariant of welded links. Furthermore we show that this is also an invariant under the other forbidden move $F_u$, and so it is a fused isotopy invariant. Also, we give some quotient ring so that the index polynomial can be an invariant for welded links.

Keywords: virtual link, welded link, Miyazawa polynomial, index polynomial, fused isotopy

MSC numbers: Primary 57M25; Secondary 57M27